Drug resistance in protozoan blood parasites of livestock across the Middle East and North Africa.

IMPORTANCE

Protozoan blood parasites, including Trypanosoma evansi, Theileria annulata, and Babesia spp., remain major constraints to livestock health and productivity across the Middle East and North Africa (MENA). Disease control relies heavily on a limited number of chemotherapeutic agents that have been used for decades, raising concern about declining efficacy and emerging drug resistance.

OBSERVATIONS: This review synthesized and critically evaluated field, experimental, and molecular evidence of antiparasitic drug resistance in major protozoan blood parasites of livestock in the MENA region. A narrative review was conducted using major scientific databases to identify peer-reviewed studies published between January 2000 and December 2025. Eligible studies reported treatment outcomes, experimental drug sensitivity, or molecular resistance markers in T. evansi, T. annulata, or Babesia spp. Evidence was organized by parasite species and evidence type; meta-analysis was not performed due to heterogeneity. The most consistent evidence of confirmed drug resistance was found for T. annulata, where buparvaquone treatment failure is repeatedly associated with mutations in the cytochrome-b and TaPIN1 genes across multiple MENA countries. For trypanosomosis, recurrent field failures and experimental resistance to diminazene and isometamidium are reported, but validated molecular markers for T. evansi remain unavailable. In babesiosis, reported outcomes indicate variable or incomplete responses to imidocarb and diminazene, reflecting functional treatment failure rather than confirmed genetic resistance.

CONCLUSIONS AND RELEVANCE: A clear mismatch exists between widespread field observations and limited molecular confirmation. Strengthened surveillance, standardized efficacy trials, rational drug use, and integrated parasite-control strategies are urgently needed in the MENA region.